Pipe Fitting Insulation, Insulation Material Melamine, Installation Style Hinged with Self-Sealing Flap, Inside Diameter 4 1/8 in, Wall Thickness 1 1/2 in, Form Tube, Minimum Operating Temperature -40 Degrees F, For Copper Tube Size 4 1/8 in, Maximum Operating Temperature 350 Degrees F, R Value 8.4, Color Gray, For Pipe Size Not Applicable, Flame Spread Index 25, Foam Cell Type Open, Plenum Rating Plenum Rated, Flexibility Semi-Rigid, Standards ASTM E84 25/50, Clean Room Class Not Applicable